[chirp_users] TSQL / CTCSS

[Jim Unroe]

> The other day my UV-5R was in scan mode and a repeater in Huntsville
> continually stopped my scan with a carrier or tone, not sure which yet. But
> I heard no audio. No matter where I set the squelch, even to 0 I got no
> audio. However, if I hit the Moni button I could hear the guys talking.
>
> What was happening here?

You have programmed a receive CTCSS tone on the frequency/channel you
were listening to. CTCSS is a form of selective squelch. When you have
a receive CTCSS tone programmed, only signals that are transmitting
the matching CTCSS tone can open your squelch. Same as a repeater that
requires tone access. If you don't transmit the matching tone, the
repeater can't hear you.

Pressing the [MONI] button overrides any programmed receive CTCSS
tone, programmed receive DCS code and SQL setting so that you can hear
any FM signal that is in range.


http://www.miklor.com/COM/UV_CTCSS.php

Jim KC9HI